After thrilling millions of riders for nearly half a century, a classic Knott's Berry Farm ride is undergoing a major renovation that will see the addition of about 60 animatronic figures.

About 50 engineers, mechanics and artisans at Garner Holt Productions are busy building animatronic lumberjacks, saloon girls, wolves and bears for the Timber Mountain Log Ride. It is to open at the end of May.

The San Bernardino-based scenic shop, the world's largest designer and manufacturer of animatronics, has outfitted dark rides at Disney and Universal theme parks around the world over the past decade.

Walter Knott famously rejected plans for a log flume — not once but twice — before giving the green light to the groundbreaking water ride that has since become Knott's Berry Farm's most popular attraction.

Legendary ride designer Wendell "Bud" Hurlbut — who conceived, built and operated Timber Mountain Log Ride with his father, Ray — was one of the first creators of theme parks in the United States.

After the success in 1960 of his Calico Mine Train at Knott's, Hurlbut began working on a log ride system with Arrow Development, a machine shop turned roller-coaster manufacturer that was instrumental in the creation of Disneyland.

After Knott turned down a pair of pitches for a sawmill-themed attraction, Arrow sold a Hurlbut-designed log flume in 1963 to Six Flags Over Texas that would become the first ride of its kind in the world.

It would be six more years before what would become known as the Timber Mountain Log Ride opened at a cost of $2.5 million at the Buena Park theme park. Together, Calico Mine Train and Timber Mountain Log Ride set the benchmark for themed attractions that sprouted up at parks around the world.

After winding through pine forests, past waterfalls and over trestle bridges, the 2,100-foot-long ride concludes with a dramatic 42-foot drop that produces an impressive bow wave.

Time has not been kind to the ride. Animated scenes have broken down. Detailed figures have been replaced with store mannequins. Raccoons have gotten into the ride and eaten some of the taxidermy animals. Seasonal Halloween overlays have made a bad situation worse.

Through the years, repeat riders have been conditioned to ignore the poorly lighted, dust-covered, animation-free vignettes.

The multimillion-dollar ride renovation draws inspiration from Hurlbut's original concepts for the ride, adding about 40 animatronic characters and 20 animated animals to the attraction.

About a third of the scenes will be new or reimagined, with some culled from unused concepts found in the Knott's archives.

Riders should notice a marked difference in the level of detail and quality when the attraction reopens May 30. Each scene will feature show lighting, weathered props and lived-in sets with lifelike animatronic figures engaged in themed activities.

During a tour of Garner Holt Productions, I got a first-hand look at all of the new animatronic figures planned for the Timber Mountain makeover.

The renovation will introduce 10 scenes that take riders past sawmills, cabins, tents, tool sheds, locomotives and steam-powered machines. Along the way, the four-person logs will travel through a forest, a valley and a tunnel. At one point, thunder and lightning will rattle through the darkness.

Animatronic characters will saw through a fallen tree, chop wood and run atop a spinning log. Other figures will laugh, swing from a rope or smoke a pipe. Each character will feature a level of detail found in a typical Disney dark ride.

During my visit to the Garner Holt factory, I watched as an employee made adjustments to a character holding onto a 25-foot-long rope ladder with one hand and a lantern light with the other.

Knott's has asked Garner Holt Productions to keep the finale scene of the renovated Timber Mountain ride, known only as the "kiss goodbye," a secret until the grand reopening.